1. Field of the Invention
This invention relates to an expansion structure for door-mounted circuit bodies which enables a circuit body on the side of a door as of an automobile--which is connector-connected with a circuit body on the side of a body as of the automobile--to be expanded and contracted with the opening and closing of the door.
2. Description of the Related Art
FIG. 11 shows a conventional door-mounted circuit body expansion structure as disclosed in Japanese Patent Application Laid-Open Specification No. 8-48146, in which a wiring harness 78 connecting a door 76 and a body 77 of an automobile is wound in the form of a coil to be expandable, and a bellows duct 79 is provided around the wiring harness 78 so as to enclose therein the wiring harness 78 as well as an air duct 80.
This structure absorbs the loosening of the wiring harness 78 at the time of opening and closing the door and enables a smooth door-opening and -closing operation. Further, since this structure does not require a waterproof grommet of rubber (not shown) such as shown in Japanese Patent Application Laid-Open Specification No. 8-33166, which is for between the door and the body of an automobile, the need for a troublesome inserting operation of the harness into a small-diameter grommet has been eliminated, leading to an improved operability for mounting.
In the above conventional structure, however, the wiring harness 78 is subject to entanglement when closing the door and thus to damages due to its binding in the duct 80, catching on the bellows duct 79 and the like. Further, confined in the bellows duct 79, the wiring harness 78 is subject to adverse effects from heat and the like.